1. Field of the Invention
This invention relates to a copolymer, and more particularly to a surgical article manufactured from the copolymer and to a method of manufacturing the copolymer and surgical article.
2. Background of the Art
Absorbable synthetic polymer sutures known in the prior art are usually manufactured, sold, and used as multifilament braids. The known absorbable polymers containing a glycolic acid ester linkage seem to be well suited for use in fabricating braided sutures. However, monofilament sutures fabricated from such polymers tend to be relatively stiff, particularly in the larger diameters. Yet, some surgeons prefer the suturing characteristics of a monofilament suture because of its smooth, continuous-surface. Thus, it has been recognized for some years that there is a need in surgery for flexible, absorbable, monofilament sutures which retain a safe and useful proportion of their strength for a relatively long period of time in vivo.
To be fully useful as an absorbable suture it is essential that a monofilament or multifilament not only be absorbable and flexible but it must also be capable of a relatively long period of in vivo strength retention. An appropriate strength retention target for this type suture is considered to be about 35-70 days in vivo.
U.S. Pat. No. 4,429,080 to Casey et al discloses a triblock copolymer wherein the end blocks comprise polyglycolide, and the middle block comprises a glycolide/trimethylene carbonate copolymer.
A new polymer has been developed for use in the fabrication of absorbable monofilament or multifilament sutures.